ઊંધુંનું ઓસડ નહીં.

ūṁdhuṁnuṁ ōsaḍa nahīṁ.

Literally: There is no medicine for the upside-down.
What it means: Some people are so fundamentally misguided that they cannot be helped.

Also said as

ગુજરાતી કહેવતસંગ્રહ (Gujarati Kahevat Sangrah) (1923) · read from the scan by machine — the Gujarati itself is unchecked · English is machine-made and nobody has checked it yet

Heard it differently, or know we've got the sense wrong? Tell us — that is exactly the kind of correction this needs.